1. Field of the Invention
The present invention relates to a solar cell and a fabrication method thereof, and in particular, to a metal wrap through solar cell including a metal wrap through (MWT) structure as a back contact silicon solar cell and a fabrication method thereof. More specifically, the present invention relates to a solar cell capable of increasing the efficiency of a solar cell by leaving only a metal finger line on a front surface of the solar cell and installing a metal electrode on a rear surface of a semiconductor substrate by penetrating through the semiconductor substrate, instead of a solar cell wherein a bus bar electrode is formed on a front surface of a solar cell according to the related art, and a fabrication method thereof.
2. Description of the Related Art
In recent years, new forms of renewable energy are of much interest due to problems, such as rising oil prices, global warming, exhaustion of fossil energy, nuclear waste disposal, position selection involved in construction of a new power plant and the like. Among others, research and development into solar cells, which is a pollution-free energy source, has actively progressed.
A solar cell, which is an apparatus converting light energy into electric energy using a photovoltaic effect, may be typed as a silicon solar cell, a thin film solar cell, a dye-sensitized solar cell, an organic polymer solar sell, and the like according to their constituent materials. The solar cell is independently used as a main power supply for an electronic clock, a radio, an unmanned lighthouse, an artificial satellite, a rocket, and the like and as an auxiliary power supply by being connected to a commercial alternating power supply. Recently, there is much growing interest into solar cells due to an increased need of alternate energy.
A solar cell to generate electricity using sunlight has generally been manufactured using silicon. Currently commercialized bulk silicon solar cells have not entered into widespread use due to high manufacturing costs and installation costs. In order to solve such problems related to the cost, research into a slim type solar cell using silicon has actively progressed and various attempts to manufacture a high efficiency solar cell module have been made.